package Demo2;

public class Test {

//站在这个角度，我不关心usb这个引用印象那个
//对象，只要你实现了这个接口的规范就好
    public static void main(String[] args) {
        Computer computer = new Computer();
        Mouse mouse = new Mouse();
        KeyBoard keyBoard = new KeyBoard();
        computer.useUsb(mouse);
        computer.useUsb(keyBoard);

    }
}
